For effective animal cell culture, intensive attention has recently been paid to culture methods based on cell properties. As a result, culture methods suitable for hybridomas and embryonic stem cells have been developed and widely used. However, methods developed to date for mass-culturing adherent cells, such as fibroblastoid cells, epithelial-type cells and the like, have not yet been perfected, suffering from the disadvantages of having a low yield and requiring a long time period for mass-scale culture.
As a technique for overcoming these problems, a cell culture tube and a cell culture system using the same were proposed.
According to this conventional technique, the mass production of animal cells can be achieved by rotating a tube bundles assembled in roller drums installed inside a housing with the aid of a motor while feeding a culture medium at a constant rate into the drum to allow the culture medium to flow into the assembled tubes, so as to distribute the cells uniformly throughout the tube due to the revolution. For the detailed constitution of this culture system, reference may be made to Korean Patent Application No. 2001-0027831, which was filed by the present inventors.
The culture system, however, is disadvantageous in that because culture influx into the tubes assembled in the roller drum is different depending on the position thereof, culture environments are different from one tube to another, leading to difficulty in realizing uniform cell culture. Also, when cells and culture media flow in and out tubes through the openings located in opposite end walls of the tubes, membranes are formed over the openings due to surface tension, making it difficult for culture media to freely move through the openings. These problems are described in detail with reference to FIGS. 2 to 4.
FIG. 2 shows a conventional roller drum 4 in which cell culture tubes 1 in a bundle are assembled. When a predetermined amount of a culture medium is provided into the roller drum 4, it gathers at the bottom of the drum 4. While the roller drum 4 rotates around a central rotating shaft 3, the culture medium flows into each cell culture tube 1.
Referring to FIG. 3, a conventional cell culture tube 1 with openings 2 formed in the opposite end walls thereof is shown in a perspective view. The openings 2 are eccentrically located at corresponding positions in contact with the edge sides of the end walls, and serve as gates through which the culture medium can flow in and out. Formed parallel to the bottom of the cell culture tube, however, the openings 2 do not allow the culture medium to freely move therethrough when surface tension occurs to thus form a drop over the opening 2.
Turning to FIG. 4, the conventional cell culture tubes 1 contain a culture medium in different amounts depending on their distances from the central rotating shaft 3. For example, a tube 1a in the proximity of the central rotating shaft 3 contains a small a mount of the culture medium while a distal tube 1b contains a relatively large amount of the culture medium. This difference is because the angle between the level of the culture medium and the cell culture tubes 1a and 1b varies depending on the how far the tubes 1a and 1b are spaced apart from the central rotating shaft 3. The difference in culture medium amount between cell culture tubes 1a and 1b results in non-uniform cell culture in the cell culture tubes.